Which of the following processes exhibits increase in internal energy?
Which of the following processes exhibits increase in internal energy?
Adiabatic compression of gas.
Adiabatic expansion of gas.
Isothermal expansion of gas.
Isothermal compression of gas.
Solution
In adiabatic process, there is no exchange of heat between system and its surroundings. So, $-\Delta \mathrm{U}=-\mathrm{W}$ or $\Delta \mathrm{U}=\mathrm{W}$ During compression work is done on the system by the surroundings. Therefore, $\mathrm{W}$ is positive. Thus, the internal energy would increase during the adiabatic compression of a gas.